EUP7961_09 EUTECH | Alldatasheet

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Technical content

DS7961 Ver 1.4 Jan. 2009 1A Ultra Low-Dropout Linear Regulator

DESCRIPTION

The EUP7961 is a 1A low-dropout linear regulator that provides a low voltage, high current output with minimum external componen ts. The features include precision output voltage, ultra-low dropout voltage, and low ground current. The EUP7961 operates from an input of 2.5V to 5.5V . This regulator uses a 1µF ceramic input capacitors and a 4.7µF ceramic output capacitor to deliver 1A output current. High bandwidth provides excellent transient response. It is designed to power digital circuits requiring low voltage with high currents (i.e., PLDs, DSPs, microcontrollers, etc.). Other features include thermal and current limit protection, a logic-control shutdown mode and an error flag output that goes low when the output voltage drops 10% below the nominal value. It is available in fixed output voltages of 1.5V , 1.8V , 2.5V , 3.3V or adjustable output voltage with a 0.8V feedback voltage. The adjustable output voltage can be set from 0.8V to 4.5V . Typical Application Circuit

FEATURES

z 1A Guaranteed Output Current z 300mV Dropout Voltage at 1A Output z Stable with Ceramic Capacitors z ±1.8% Output Voltage Accuracy z 300µA Low-Ground Pin Current 0.1µA Quiescent Current in Shutdown Mode z Excellent Line and Load Regulation z Thermal Shutdown and Current Limit Protection z Error Flag Indication z Available in SOT223, SOP-8 and SOT-89 Packages z RoHS Compliant and 100% Lead (Pb)-Free

APPLICATIONS

z Supply for Low-Voltage Digital IC z PC Add-In Cards z High Efficiency Linear Power Supplies z Post Regulator Figure1.

DS7961 Ver 1.4 Jan. 2009 Block Diagram Figure2. Pin Configurations Package Type Pin Configurations Package Type Pin Configurations SOT223-3 SOT223-3 (B) SOT223-3 (C) SOT-89 SOP-8

DS7961 Ver 1.4 Jan. 2009 Pin Description PIN SOT-223 SOT-223 (B) SOT-223 (C) SOT-89 SOP-8 DESCRIPTION VEN - - - - 1 Enable Input. Logic high=enable, Logic low=shutdown VIN 1 3 2 3 2 Input V oltage of the LDO GND 2 1 1 2 5,6,7,8 Ground: TAB is connected to ground VOUT 3 2 3 1 3 Output voltage of the LDO ERROR ERROR Flag Output. Active-low indicated an output fault condition ADJ - - - - 4 Adjustable Regulator Feedback Input. Connect to resistor voltage divider

Ordering Information

Order Number Package Type Marking Operating Temperature Range EUP7961-15BIR1 SOT223 xxxxx P7961C -40 °C to +85°C EUP7961-18BIR1 SOT223 xxxxx P7961D -40 °C to +85°C EUP7961-25BIR1 SOT223 xxxxx P7961B -40 °C to +85°C EUP7961-33BIR1 SOT223 xxxxx P7961H -40 °C to +85°C EUP7961B-15BIR1 SOT223 xxxxx 7961CB -40 °C to +85°C EUP7961B-18BIR1 SOT223 xxxxx 7961DB -40 °C to +85°C EUP7961B-25BIR1 SOT223 xxxxx 7961BB -40 °C to +85°C EUP7961B-33BIR1 SOT223 xxxxx 7961HB -40 °C to +85°C EUP7961C-15BIR1 SOT223 xxxxx 7961C 1 C -40 °C to +85°C EUP7961C-18BIR1 SOT223 xxxxx 7961C 1 D -40 °C to +85°C EUP7961C-25BIR1 SOT223 xxxxx 7961C 1 B -40 °C to +85°C EUP7961C-33BIR1 SOT223 xxxxx 7961C 1 H -40 °C to +85°C EUP7961-15CIR1 SOT-89 xxxxx P7961C -40 °C to +85°C EUP7961-18CIR1 SOT-89 xxxxx P7961D -40 °C to +85°C EUP7961-25CIR1 SOT-89 xxxxx P7961B -40 °C to +85°C EUP7961-33CIR1 SOT-89 xxxxx P7961H -40 °C to +85°C

DS7961 Ver 1.4 Jan. 2009 Ordering Information (continued) Order Number Package Type Marking Operating Temperature Range EUP7961-15DIR1 SOP-8 xxxxx EUP7961 C -40 °C to +85°C EUP7961-18DIR1 SOP-8 xxxxx EUP7961 D -40 °C to +85°C EUP7961-25DIR1 SOP-8 xxxxx EUP7961 B -40 °C to +85°C EUP7961-33DIR1 SOP-8 xxxxx EUP7961 H -40 °C to +85°C EUP7961DIR1 SOP-8 xxxxx EUP7961 A -40 °C to +85°C Lead Free Code 1 : L e a d F r e e 0 : L e a d Packing R : T a p e & R e e l Operating temperature range I: Industry Standard P a c k a g e T y p e : B : S O T 2 2 3 C : S O T 8 9 D : S O P O u t p u t V o l t a g e

DS7961 Ver 1.4 Jan. 2009 Absolute Maximum Ratings (1) „ Package Thermal Resistance „ Power Dissipation, PD@TA= +25°C „ ESD Rating Recommended Operating Conditions (2) Note (1): Stress beyond those listed under “Absolute Maximum Ratings” may damage the device. Note (2): The device is not guaranteed to function outside the recommended operating conditions.

Electrical Characteristics

Specifications in standard type face are for TA= +25°C, and those with boldface type apply over the full operating temperature range TA= -40°C to +85°C. VIN=VOUT(NOM)+1V, VEN＝5V, IL=10mA, CIN=COUT=4.7µF unless otherwise specified. EUP7961 Symbol Parameter Conditions Min Typ Max. Unit VOUT+1V ≤ VIN ≤ 5.5V 10mA ≤ IL ≤ 1A T A= +25°C -1.8 1.8 Output V oltage Tolerance VOUT+1V ≤ VIN ≤ 5.5V 10mA ≤ IL ≤ 1A T A= -40°C ~ +85°C -3 3 Line Regulation V OUT+1V ≤ VIN ≤ 5.5V 0.1 0.24 % ΔVOUT Load Regulation 10mA ≤ IL ≤ 1A 0.08 0.32 % IL = 100mA 35 50 VIN -VOUT Dropout V oltage IL = 1A 300 500 mV IL = 10mA 300 360 Ground Pin Current in Normal Operation Mode IL = 1A 500 600 µA IGND Ground Pin Current in Shutdown Mode VEN ≤ 0.3V 0.01 10 µA IO(PK) Peak Output Current V O ≥ VO(NOM) -4% 1.1 1.5 A Short Circuit Protection ISC Short Circuit Current 1.2 1.7 A

DS7961 Ver 1.4 Jan. 2009 Electrical Characteristics (continued) Specifications in standard type face are for TA= +25°C, and those with boldface type apply over the full operating temperature range TA= -40°C to +85°C. VIN=VOUT(NOM)+1V, VEN＝5V, IL=10mA, CIN=COUT=4.7µF unless otherwise specified. EUP7961 Symbol Parameter Conditions Min Typ Max. Unit VIH Output = High 1.4 VIN VIL Enable Threshold Output = Low 0 0.3 V TdOFF Turn-off delay I L = 1A 20 50 TdON Turn-on delay I L = 1A 20 50 µs IEN V EN Pin Input Current V EN=VIN -1 1 µA ERROR Flag VT Threshold 8 10 12 % VTH Threshold Hysteresis 5 % VEF(Sat) ERROR Flag Saturation ISINK=100µA 0.02 0.1 V Td Flag Reset Delay 1 µs IIK ERROR Flag Pin Leakage Current 1 nA Imax ERROR Flag Pin Sink Current VError=0.5V 3.8 mA AC Parameters PSRR Ripple Rejection VIN=VOUT+1V COUT=10uF VOUT=3.3V , f=120Hz 60 dB en Output Noise V oltage BW=10Hz -100kHz VOUT=2.5V 150 µV(rms) Over Temperature Protection TSH(t) Shutdown Threshold 150 °C TSH(h) Thermal Shutdown Hysteresis 10 °C

DS7961 Ver 1.4 Jan. 2009 Typical Operating Characteristics

DS7961 Ver 1.4 Jan. 2009 Typical Operating Characteristics (continued)

DS7961 Ver 1.4 Jan. 2009 Application Note Input Capacitor An input capacitance of 1µ F is required between the EUP7961 input pin and ground (the amount of the capacitance may be increased without limit).This capacitor must be located very close to the input pin and returned to a clean analog ground. Any good quality ceramic, tantalum, or film cap acitor can be used at the input. If a tantalum capacitor is used at the input, it must be guaranteed by the manufacturer to have a surge current rating sufficient for the ap plication. There are no requirements for the ESR on the input capacitor, but tolerance and temperature coef ficient must be considered when selecting the capacitor to ensure the capacitance will be 1µF over the entire operating temperature range. Output Capacitor The EUP7961 is designed specifically to work with small ceramic output capacitors. A ceramic capacitor (temperature characteristics X7R, X5R, Z5U, or Y5V) in 4.7µF to 22µF range with 5m Ω to 200mΩ ESR range is suitable in the EUP7961 application circuit. The output capacitor must meet the requirement for minimum 4.7µF over the entire operating range and also have an ESR (Equivalent Series Resistance) value which is within a stable range (5mΩ to 200mΩ) No-Load Stability The EUP7961 will remain stable and in regulation with no external load. This is specially important in CMOS RAM keep-alive applications. On/Off Input Operation The EUP7961 is turned off by pulling the VEN pin low, and turned on by pulling it high. If this feature is not used, the V EN pin should be tied to VIN to keep the regulator output on at all time. To assure proper operation, the signal source used to drive the V EN input must swing above and below the specified turn-on/off voltage thresholds listed in the Electrical Characteristics section under VIL and VIH. ERROR Flag Operation The EUP7961 produces a logic low signal at the ERROR Flag pin when the output drops out of regulation due to low input voltage, current limiting, or thermal limiting. This flag has a built in hysteresis. The ERROR is an open drain output. Hence, the ERROR pin should be pulled high through a pull up resistor. The ERROR pin must be connected to ground if this function is not used. In shutdown, the ERROR pin is Hi-Z state to save input power. Adjustable Operation The adjustable version of the EUP7961 has an output voltage range of 0.8V to 4.5V . The output voltage of the EUP7961 adjustable regulator is programmed using an external resistor divider as shown in Figure3. The output voltage is calculated using: Where: Vref= 0.8V typ. (the internal reference voltage) Utilize the following equation for adjusting the output to a particular voltage: Choose R 2=50k to optimize accuracy, power supply rejection, noise and power consumption. Power Dissipation EUP7961 can deliver a continuous current of 2A over the full operating temperature range. A heatsink may be required depending on the maximum power dissipation and maximum ambient temperature of the application. Under all possible conditions, the junction temperature must be within the range specified under operating conditions. The total power dissipation of the device is given by: ( ) ( ) GNDI INVOUTI OUTVINVDP +−= Where IGND is the operating ground current of the device (specified under Electrical Characteristics). The maximum allowable temperature rise (T Rmax) depends on the maximum ambient temperature (T Amax) of the application, and the maximum allowable junction temperature (T Jmax): TRmax= TJmax-TAmax The maximum allowable value for junction to ambient Thermal Resistance, θ JA , can be calculated using the formula: θJA =TRmax/PD R (1VV refO +×= −= 10.8V V RP O

DS7961 Ver 1.4 Jan. 2009 PCB Layout Good PCB layout practices must be used, otherwise instability can be induced b ecause of ground loops and voltages drops. The input and output capacitors must be directly connected to the input, output, and ground pins of the regulator using traces which do not have other currents flowing in them.The best way to do this is to lay out C IN and COUT near the device with short traces to the VIN, V OUT, and ground pins. The regulator ground pin should be connected to the external circuit ground so that the regulator and its capacitors have a “single point ground”.

DS7961 Ver 1.4 Jan. 2009 Packaging Information SOT223-3 MILLIMETERS INCHES SYMBOLS MIN. MAX. MIN. MAX. A 1.50 1.80 0.059 0.071 A1 0.00 0.10 0.000 0.004 B 0.60 0.80 0.024 0.031 B1 2.90 3.10 0.114 0.122 D 6.50 0.256 E 3.50 0.138 e 2.30 0.090 H 6.70 7.30 0.264 0.287 L 0.80 1.10 0.031 0.043

DS7961 Ver 1.4 Jan. 2009 SOP-8 MILLIMETERS INCHES SYMBOLS MIN. MAX. MIN. MAX. A 1.35 1.75 0.053 0.069 A1 0.10 0.25 0.004 0.010 D 4.90 0.193 E 5.80 6.20 0.228 0.244 E1 3.90 0.153 L 0.40 1.27 0.016 0.050 b 0.31 0.51 0.012 0.020 e 1.27 0.050

DS7961 Ver 1.4 Jan. 2009 SOT-89 MILLIMETERS INCHES SYMBOLS MIN. MAX. MIN. MAX. A 1.40 1.60 0.055 0.063 L 0.89 1.20 0.035 0.047 B1 0.36 0.48 0.014 0.019 B 0.44 0.56 0.017 0.022 C 0.35 0.44 0.014 0.017 D 4.40 4.60 0.173 0.181 D1 1.35 1.83 0.053 0.072 H 3.94 4.25 0.155 0.167 E 2.29 2.60 0.090 0.102 e 1.50 0.059